The edge were tree meets field creates a haven for all sorts of critters.
Streamside Balsam Poplar
Balsam Poplar love water. This fine specimen is about 20 feet away from the edge of my pond, and by itself is probably responsible for an centimeter or so of pond water each summer.
The spruce forest was forever. But lightning struck either as a true electrical discharge or the strike of the axe, and crosscut saw, and the spruce was laid low.
The forest goes down. The ground is laid bare. Every year half the poplar for miles around release millions of cottony seeds that blow freely on the wind. Most die, unsprouted. Many sprout, but can't compete against every other airborne seed that wanders in.
But every few hundred feet, one starts, and manages to get a leaf up into the sun.
Poplar, either aspen in drier areas, or balsam in wetter areas, is the first tree to naturally establish itself after land has been cleared either by fire or by man's activities.
Soon the weeds are far behind. Once well established with tips above all the surrounding weeds, and out of reach to moose and deer, the poplar start the young tree engages in venture capitalism. Shoots sprout upward from far flung roots. In this way, the forest will spread, 10, 20, 30 feet per year.
I first noticed this wild flower, not here on my own land, but on a canoe trip in northern Saskatchewan. I took pictures. On showing them to Laura she commented, "Aren't there some of those on the potyard trail?"
Indeed there were.
Unlike spruce, poplar forests have an understory. The understory varies. In fact, in the five years we've been here, different plants have come up each year. Among the shrubs are wild rose, dogwood and wild raspberry. Smaller plants include lungwort, Canadian dogwood, white violets, bedstraw. Disturbed land tends to go to thistle and nettles. Occasionally in a sunny spot you'll see a tiger lily. Here and there a chokecherry.
In one sense a grove of poplar may only be a single organism. The tops appear to be different but they are all connected underground. In the fall you can see this: All the trees in a connected clump, are genetically identical. They all lose their leaves on almost the same day. Look at the river valleys next fall. You will see that the leaf fall doesn't vary by tree, but by great swaths of trees.
The natural ecology of central Alberta is called "aspen parkland" It's a stable mix of grassy areas and zones covered by aspen. The map of the mix varies from year to year. And fire was part of that mix.
A prairie fire would kill young poplar and young spruce both. But a tall healthy poplar tree could survive a quick grass fire unharmed. In a series of dry years there would be lots of grass fires. Young poplar would get killed. Some old poplar died on the edges of the groves. The grass would advance, the poplar retreat.
In a series of wet years, there wouldn't be as many grass fires. More poplar shoots would survive. The poplar would advance on the grass. An uneasy balance eresulted. Dry areas such as hilltops, south facing slopes, were almost always grass. Creek bottoms, ravines, north facing slopes were almost always poplar. The rest? The rest was up for grabs.
I'm sure this explanation is too simple. It's never this easy. Really.
Got something to say? Email me: sfinfo@sherwoods-forests.com
Interesting? Share this page.
Want to talk right now? Call me: (8 am to 8 pm only, please) 1-780-848-2548
Do not arrive unannounced. Phone for an appointment. Why? See Contact & Hours That same page gives our hours of operation.
Back to Top
Copyright © 2008 - 2021 S. G. Botsford
Sherwood's Forests is located about 75 km southwest of Edmonton, Alberta. Please refer to the map on our Contact page for directions.